Leaves with brown rusty spots

Crescendo

Member
Hi! One of my plants is showing brown rusty spots on the leaves, mostly at the top. The plant is grown in soil and feeding biocanna nutes. I've been regularly checking Ph and never went above 6.5 value.

The rest of the plant seems healthy but I wish to understand what does the sign the pics correspond to so can take prompt action. Thanks!
 

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Hobbes

Well-Known Member
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Hi Crescendo

It looks like the start of Mg deficiency, feeding her CalMag like you're doing should stop the spread but the damaged leaves are here until you defoliate.

,
 

Crescendo

Member
This is helpful but it still confuses me somehow. If I look at it, rusty spot could be a calcium deficiency or a boron one or a manganese excess. I'm still far from being able to fully recognize the differences and causes. Anyways, I'll go easy on nutes from now onwards and ensure a calmag dose as well. Also what surprises me is these spots literally appeared within 24 hours and increasing fast!

Do you suggest me to keep these leaves or cut them off?
 
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Hobbes

Well-Known Member
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You look to be at about 4-5 weeks of flower, new leaves won't grow back in time.

Those leaves still have plenty of green, and the are a good metric if the deficiency is halted or spreading.

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Dontjudgeme

Well-Known Member
Hi! One of my plants is showing brown rusty spots on the leaves, mostly at the top. The plant is grown in soil and feeding biocanna nutes. I've been regularly checking Ph and never went above 6.5 value.

The rest of the plant seems healthy but I wish to understand what does the sign the pics correspond to so can take prompt action. Thanks!

What kind of water are you using?
 
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